Bummer! This is just a preview. You need to be signed in with a Basic account to view the entire video.

Preview

Start a free Basic trial
to watch this video

Sign up for Treehouse

Working with Hash Values

2:00 with Jason Seifer

So far, we've learned how to create and modify hashes and work with hash keys. Ruby provides several ways to work with the values in a hash as well. In this video, we'll explore different ways to work with the values in a hash.

Code Samples

For the examples below, we'll be working with this hash:

hash = { "item" => "Bread", "quantity" => 1, "brand" => "Treehouse Bread Company" }

To return an array of the values in the hash, we can use the values method:

hash.values

Which would return the following:

["Bread", 1, "Treehouse Bread Company"]

The has_value? method takes one argument and returns true or false if the value is contained within the hash:

hash.has_value?("brand")

That would return false since "brand" isn't a value. However, the following would return true:

hash.has_value?("Bread")

The values_at method takes several arguments and returns the hash values at the specified keys as an array:

hash.values_at("quantity", "brand")

That would return:

[1, "Treehouse Bread Company"]
  • 0:00

    Similarly, the hash keys, Ruby provides us methods for working with hash values.

  • 0:07

    Let's take a look of some of those now using WorkSpaces.

  • 0:10

    Okay, so I've just created a new ruby WorkSpace here and

  • 0:14

    here we are in the console.

  • 0:15

    Let's go ahead and launch an RIB session and start working with hash values.

  • 0:21

    So let's create a hash to work with.

  • 0:24

    The item here is gonna be bread, quantity of 1 and

  • 0:29

    the brand is still gonna be Treehouse Bread Company.

  • 0:37

    All right, so here is a hash to work with.

  • 0:40

    Now just like the method for looking at all the keys was called hash dot keys,

  • 0:46

    we have a similar method to look at all the values called values.

  • 0:51

    And that will return an array of all of the different values inside of the hash.

  • 0:57

    And again how we asked the hash if it had a key, and passed in an argument.

  • 1:03

    We can do the same thing to see if it has a value.

  • 1:06

    So we could say hash.has_value, and

  • 1:09

    then pass in a value it does not have the value brand because that's a key, but

  • 1:15

    let's see if it has a value for the number one which is the quantity and it does.

  • 1:25

    And we can also use the method value and pass in an argument.

  • 1:30

    It's pretty much the exact same thing, an alias under a different name.

  • 1:36

    If we wanted to get a couple values back from the hash,

  • 1:39

    we could use the values add method and pass in the keys that we want.

  • 1:45

    We'll say we want item and quantity and

  • 1:48

    that will return an array of the values for the keys that we passed in.

  • 1:54

    Try practicing with hashes and hash values on your own now using WorkSpaces.

You need to sign up for Treehouse in order to download course files.

Sign up